Self-cleansing filter.



No. 880,558. PATENTED MAR. 3, 1908.

B. METGALP. SELF CLEANSING FILTER.

' APPLIOATIONI'ILED AUG. 19, 1905.

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,PATENTED MAR. 3, 1908.

B. METCALF.

SELF CLEANSING FILTER.

APPLICATION FILED AUG. 19, 1905.

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No. 880,558. PATENTED MARPB, 1908. B. METGALF. v r SELF CLEANSINGFILTER;

APPLICATION FILED AUG. 19, 1905.

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,BRYOE METOALF, or NEW YORK, N. Y.

SELF-CLEANSING FILTER.

Specification of Letters Patent.

Patented March 3, 1908.

Application filed August 19. 1906- Serial No. 274,890.

To all whom it may concern:

Be it known that I, BRYCE METoALF, a citizen of the United States,residing in the borough of Manhattan, New York city, county and State ofNew York, have in vented certain new and useful Improvements inSelf-Cleansing Filters, of which the following is such a full, clear,and exact description as will enable any one skilled in the art to whichit appertains to make and use the same, reference being had to theaccompanying drawings, forming part of this specification.

My invention relates to filters for purifying water and in which thefilter medium or body is automatically cleansed by the water in thefilter, such a general type of filter being found in U. S. LettersPatent No. 789,751, granted to me May 16th, 1905. In operating filtersof this type, I have found that where small quantities of filtered waterare drawn off, such for example as a glass of water, it is not onlyunnecessary to wash or cleanse the filter-medium after each operation ofthe fil ter, but that this frequent washing or cleansmg wastes aconsiderable quantity of water.

The principal objects of my present invention are to provide aself-cleansing filter in which the cleansing action does not take placeat each operation of the means for drawing oil the filtered water, butoccurs only after several, or a predetermined number of operations ofsuch drawing-off means. For instance, instead of causing the filter tocleanse itself after it is operated to draw off one glass of water, Ihave so designed it that the cleansing operation takes place after thefilter has been operated to draw off several difl'erent quantities ofwater.

ith these and other objects in view, my invention consists in thevarious novel and peculiar arrangements and combinations of the severalparts of the apparatus, all as hereinafter fully described and thenpointed out in the claims.

I have illustrated a type of my invention in the accompanying drawings,wherein Figure is a side view of a self-cleansing filter and coolerembodying my invention, part of the casing being shown as broken awayand in vertical section. Fig. 2 is a perspective view of the apparatusshown without the casing and the support thereof. Fig. 3 is a centralvertical sectional view of the self-cleansing filter itself with itsthree pipe-connections. Figs. 4, 5 and 6 are central sectional views ofthe different valves contained in the apparatus.

Referring to the drawings, in which like numbers of reference designatelike parts throughout, 1 is the exterior casing of the filter,substantially like that shown in my Letters Patent No. 789,751, to whichreference may be had for a full and complete description thereof. Thefilter body or medium 9, is mounted within the casing 1, so

that there is provided between the same and the casing anannular-chamber 12, which constitutes the unfiltered water chamber, theunfiltered water being supplied to the chamber 12, under pressure,through the pipe 19, while the filtered water is drawn off from theinterior of the dome 5, by the drawing-off pipe 21, which. communicatestherewith through the passage 20.

In the operation of this type filter, the water being supplied underpressure through pipe 19, to the chamber 12, the water is forced thencethrough the filtering medium 9, and the filtered-water begins to rise inthe dome 5, confining the air above it and placing such air under thepressure of the main, from which the water is supplied. Under thiscondition when the draw-oif pipe 21 is opened the filtered water willpass from the dome 5, under pressure of the air above it. Upon closingthe draw-off pipe 21, likewise the supply pipe 19, and immediatelyopening the waste-pipe 3, the filtered water remaining in the dome isthen forced back through the filter-medium 9, over the reverse courseover which it has previously passed in bein filtered, and under pressureof the air in tie dome and this back-wash cleanses the filter and passesthence out of the waste 3. The operation just described is that found inmy present invention, how ever, I do not open the waste-pipe after eachfiltering or drawing off operation, but only open the waste for thepurpose of cleansing the filter, periodically, and after severaloperations of the drawing-off means.

In the construction herewith shown, two filters are illustrated but thesystem applies to one filter, or to more than two, equally well and indescribing the construction and operation of the apparatus only onefilter need be considered. The supply pipe 19, which may be connectedwith an ordinary water-main, is providedwvith a valve 25 having a valveseat 26 and provided with a valve-stem 27, having a spring 28 fornormally keeping the valve closed on its seat. The valve stem is actedupon by a lever or trip 29, pivoted at toia projection on the valvecasing 25, and this lever is in turn signed to keep the supply valve 25open the greater part of the time and a quick closing of the valve isdesirable, (as w1ll be understood from the description of the remainingparts of the apparatus) I therefore, construct this cam with this lostmotion on its shaft, whereby the cam-lever 29, under action of spring 28of the valve, may snap the cam around and allow the supply valve to bequickly closed by its spring.

The drawing-off pipe 21 is provided near its outlet 21 with a coil 36,which is used for the purpose of cooling the contents of the pipe by icewhich is indicated at 37, in Fig. 1. A valve 38 is located in thedrawing-off ipe and is normally kept closed by a spring 39 on its valveseat 40, the stem 41 of this valve being engaged by a hand-operatedlever 42, which is pivoted at 43 to a suitable fixed point, so that ateach depression of lever 42 the draw-off valve 38, is opened.

In this type of filter, in which the filter body is cleansed by aback-wash of the filtered water which receives the pressure 7 from theair confined in the dome, the initial filtering operation is somewhatslow, so that upon opening the drawing-0E faucet the filtered water doesnot immediately begin to fiow therefrom, for the obvious reason that ittakes a few moments for the filtered.

water to accumulate in the dome. While this is not particularlyobjectionable it is, nevertheless not a desirable feature to have in afilter, and I 5 have entirely overcome this, and do so by locating at asuitable point in the draw-off pipe connections, a storage chamber orpressure reservoir 44, in which the filtered water may accumulate and bestored during-the time the draw-off valve or faucet is closed so thatimmediately upon opening the draw-off valve there is a copious supply offiltered water under full pressure, from the outlet 21. Between thisstorage and pressure chamber 44 and the filter itself, there is locateda valve 45, having a casing 45", and which is normally kept closed onits seat 46 by a spring 47, and the stem 48 of this valve is pushed uponby a cam 49, also mounted on the cam-shaft 32, and having a slight lostmotion by means of a slot 50, in the. cam-hub and a fixed pin 51, on thei as having eight teeth.

The waste pipe 3, leading from the filter is provided with a valve 49,which is the same as valve 25, which controls the supply-pipe, and thisvalve is likewise provided with a cam-lever 50 pivoted at 51 and actingto control the valve 49 in the same Way as the camlever 29, controls itsvalve 25, though at a different time. The cam-lever 50', controlling thewaste valve, is operated by a cam 52, mounted on the cam shaft 32 andhaving a slight lost motion thereon by means of a slot 53. on the hub ofthe cam and a fixed pin 54 on the shaft, so as to permit this cam tosnap around and allow the valve 49 to be quickly closed at the propertime. This waste valve cam 52 has comparatively small high-part for thereason that this cam is intended. to keep the waste valve open but acomparatively short time and that occurs but once during everyrevolution of the cam shaft 32.

The cam shaft 32 is operated by a step-bystep mechanism which in turn isactuated. by

the hand-operated lever 42 of the draw-off means. This step-by-stepmechanism comprises a ratchet wheel 55, which is here shown This wheel55 is fixed on the camshaft 32, so as to turn the shaft and a spring dog56 engages the teeth of the ratchet to prevent backward rotation. Theratchet-wheel 55 is engaged by a pawl 57 which is pivoted at 58 to thehand-lever 42, and the lever is provided at a suitable point with. aweight 59 which serves to normally keep the lever off the valve stem 41of the draw-off valve and to hold the pawl 57 in position to engage atooth on the ratchet whenever the lever is depressed to open thedraw-off valve 38.

The various parts of the apparatus are so related and adjusted that thewaste-valve 49 cannot be opened while either supply-valve 25, or theauxiliary valve 45 is open and so that both of the last mentioned valvesmay simultaneously be open while the wastevalve is closed. Consideringnow thevarious cams in the relative positions shown in Fig. 2, thedraw-oif valve 38 is closed, the supply valve 25 is open, likewise theauxiliary valve 45, while the waste valve 49 is closed. This conditionpermits the filtered. water to rise to the highest point in the dome 5.,and compress the air therein and' then to flow from the dome 5 throughthe filtered water pipe 21 by way of the open valve 45 to thestoragechamber 44, which is likewise filled to its highest point andwith the air under pressure therein the draw-off pipe 21 is also filledwith filtered water down as far as the valve 38. Upon depressing thehand lever 12 and opening the valve 38 the filtered water may be drawnoff from the outlet 21 and this same operation of the lever turns theratchet wheel 55 one tooth, thereby turning the camshaft one eighth of arevolution and moving the three cams on the shaft accordingly. Uponreleasing the hand lever 12 the valve 38 is closed and the apparatusreset for the next following operation thereof in drawing off filteredwater. The apparatus may be operated in the way ust described a numberof times without the waste valve being opened and with the supply andauxiliary valves maintained open. When, hon ever, the cam shaft has beenturned so that the cam 52 is brought into position to operate the camlever 50, on the next depression of the hand-lever #12, the cam of boththe supply and auxiliary valves stand ready to close their respectivevalves immediately upon the waste valve being opened on the nextoperation of the hand lever.

In the operation of the hand lever in drawing off filtered water, whenthe waste valve is opened and the other valves closed, the filteredwater then drawn off is obtained from the storage chamber 44, as theauxiliary valve .15, is at that time closed and the filtering operationis for the time being, suspended. Upon the next succeeding operation ofthe hand-lever 42, in drawing off the filtered water, the three valvesremain in the same positions thereby giving ample time for the cleansingprocess to take place, it being immaterial how long the waste valveremains open for the .oleansing process, since the only water which canthen pass from the filter being the quantity of filtered water remainingin the dome for the backwash. Upon the next succeeding operation of thehand lever, the waste-valve is quickly closed and the sup ly andauxiliary valves are at once opened. It will thus be seen that at eachoperation of the hand-lever, the drawing off valve 38 is opened andfiltered water is discharged from the outlet 21*, but that the cleansingprocess does not occur but once during each revolution of the cam-shaft32, such revolution being completed, in the construction herewith shown,by ei ht operations of the hand-lever, so that the c eansin only takesplace once out of eight times t at the filter is operated. Thispredetermined number of operations of the filter before cleansing it maybe varied as desired and to suit the particular conditions. In actualpractice I have found that the present construction is a good one andthat the filter body is kept thoroughly cleaned by cleansing it once outof eight operations of the drawing off means.

At a suitable point in the supply pipe 19,

I provide an air Valve 7 O, by means of which the outer air is admittedto the supply in order to eventually replace the air in the dome 5,which escapes therefrom during the back-wash when the filter iscleansed. A full description of the construction and operation of asimilar air valve is found in my said Letters Patent No. 789,751.

In Fig. 1, I show a constructon of a combined filter and water coolingapparatus which is provided with a casing 60, having supports or legs61, for elevating the apparatus to the proper height, the casing containing a compartment 62 for the pipe coil 36 and the ice 37, with adrain-pipe 63 extending from the bottom of the compartment to the wastepipe 3. The filter 15, is placed in a compartment 64 within the casing60, likewise the various valves and cams for actuating the same, thehand-lever 42 pro j ecting from the front of the casing in a position tobe easily handled by a person, likewise the outlet 21 of the drawing offpipe 21; a drip-receptacle 65 beng placed beneath the outlet andconnected with the waste 3 by pipe 66. In this form of apparatus thestorage pressure chamber 44 is shown as of considerable size and placedbeneath the casing 60 with the drawing off pipe 21 leading into the topof the chamber,

the action of which is the same as that already described in Fig. 2. u

I wish to be understood as not limiting my invention to the specificforms of the various different parts thereof as herewith set forth, asvarious modifications may be made in the different parts thereofwithout, however, departing from the spirit of my invention.

Having thus described my invention What I claim and desire to secure byLetters Patent is:

1. A self-cleansing filter having unfiltered water supplied theretounder pressure and provided with means for drawing off the filteredwater, a step-by-step operated mechanism for automatically causing abackwash of filtered water through thefilterbody, such mechanism beingoperated after several operations of the said drawing-0E means.

2. A self-cleansing filter having unfiltered water supplied theretounder pressure and provided with means for drawing ofi the filteredwater, mechanism for automatically causing a backwash of filtered waterthrough the filter-body, such mechanism being operatively connected withand controlled by said drawing-off means and being actuated afterseveral successive operations of said drawing-off means.

3. A self-cleansing filter having unfiltered water supplied theretounder pressure and provided with means for drawing ofi the filteredwater, means for automatically confining air within the filter under thesaid pressure of the water therein, mechanism for causing a back wash offiltered water through the filter-body under the pressure of the airthus confined in the filter to cleanse the filter, and such mechanismbeing operated after several operations of said drawingoff means.

4. A self-cleansing filter provided with means for drawing off thefiltered water and having unfiltered Water supplied thereto underpressure, means for confining air within the filter under, the saidpressure of the water therein, mechanism for forcing filtered waterthrough the filter body under the pressure of such air to cleanse thefilter and such mechanismbeing operated after several operations of saiddrawing off means, substantially as and for the purpose set forth.

5. A self-cleansing filter provided with means for drawing 0H thefiltered water, and mechanism for cleansing the filter with the watertherein, a step-by-step device intermediate between said drawing offmeans and the mechanism for cleansing the filter and said stepby-stepdevice being actuated by each operation of said drawing off means butactuating said cleansing mechanism after several step-by-step movementsof said device, substantially as and for the purpose set forth.

6. A self-cleansing filter having pipe connections provided with a valvefor controlling the same for drawing off the filtered water, a wasteoutlet for carrying off the waste water from the cleansing of the filterand provided with a valve controlling the 'same, connections between thetwo said valves of the drawing ofi pi e and the waste, andv means foroperating t e same by hand whereby at each operation thereof the saidvalve of the drawing off pipe may be open while the valve of said wasteremains closed until after several operations of said drawing off means,substantially as and for the purpose set forth.

7. A self-cleansing filter provided with a supply pipe having a valvecontrolling the same, a waste-outlet also provided with a valvecontrolling the same, pipe connections for drawing off the filteredwater and provided with a valve controlling such action,

and means for actuating the valve of said actuating said waste valveperiodically for cleansing the filter, substantially as and for thepurpose set forth.

8. A selfcleansing filter having an unfiltered Water chamber providedwith a water'supply, a filtered water chamber provided with valved meansfor drawing the water therefrom, a filtering medium, means for confiningthe air above the filtered water under pressure of said water, the waterbeing supplied to the unfiltered water chamber more rapidly than thewater is drawn off from the filtered water .chamber, the said drawingoff means being provided with a storage pressure chamber and anauxiliary valve located between the said filter and the storage chamberand means for periodically operating it during the successive operations0 the valve of said drawing off means, substantially as and for thepurpose set forth.

In testimony whereof, I have hereunto set my hand in the presence of thetwo subscribing witnesses.

BRYCE METCALF. \Vitnesses:

WILLIs FOWLER, WILLIAM A. STEIN.

